SAE AMS 6484: 2016 [pdf]

SAE AMS 6484 – Steel, Bars, Forgings, and Tubing 0.80Cr – 1.8Ni – 0.25Mo (0.38 – 0.43C) (SAE 4340) Normalized and Tempered (Rev. F)

Covers an aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock

These products have been used typically for parts, 3.5 inch (89 mm) and under in nominal thickness at time of heat treatment, requiring a through-hardening steel capable of developing a minimum hardness of 40 HRC when properly hardened and tempered and also for parts of greater thickness requiring proportionately lower hardness, but usage is not limited to such applications

Certain design and processing procedures may cause these products to become susceptible to stress-corrosion cracking after heat treatment; ARP1110 recommends practices to minimize such conditions

Search terms: AMS6532, AMS6532F